Disgraced New York Yankees third baseman Alex Rodriguez was busted in the ladies room at the Delano Hotel in Miami with a mystery brunette who most certainly was not his blond girlfriend Torrie Wilson, sources exclusively tell Confidenti@l.

Torrie Wilson/Instagram

On Monday night, Wilson tweeted a photo of the couple at a surprise fete for Yankees legend Mariano Rivera (right), saying, ‘So cool to spend a night honoring Mariano Rivera.’

A-Rod had been dining at the UMI Sushi & Sake Bar at the trendy South Beach hotel on Saturday night with an entourage. A hotel guest tells us the Yankee, who is facing suspension over his performance-enhancing drug scandal, was first spotted getting hot and heavy with the unidentified woman near the elevators in the hotel lobby early Sunday morning.

KDNPIX

Alex Rodriguez and girlfriend Torrie Wilson last month after hitting a gym. She wasn’t around on his recent excursion to the Delano in South Beach.

The duo soon disappeared into the women’s bathroom, where we hear they spent nearly 20 steamy minutes. A-Rod and the mystery lady allegedly became flustered and decided to end their toilet tryst when they were interrupted by another hotel guest.

Tom Grizzle

A rep for the Delano (pictured) said the hotel does not comment on guests on the property.

Earlier on Saturday, A-Rod was seen tailgating at the University of Miami’s football game against Virginia Tech at Sun Life Stadium in Miami Gardens, Fla. He posed for pictures with six female fans, including one who made it to Instagram with the caption: “A-Rod Reppin the U.” It was the second straight week he had watched the ’Canes lose. The week before, he traveled to Tallahassee to tailgate with fans before Florida State beat “The U.”

A-Rod has been dating Wilson, a former Playboy model and WWE wrestler, since late 2011, following his high-profile breakup with Cameron Diaz. On Monday night, Wilson tweeted a photo of the couple at a surprise fete for Yankees legend Mariano Rivera, saying, “So cool to spend a night honoring Mariano Rivera.”

Kathy Willens

A-Rod has been dating Torrie Wilson, a former Playboy model and WWE wrestler, since late 2011.

In his book due out in March, “House of Outrageous Fortune: Fifteen Central Park West, the World’s Most Powerful Address,” author Michael Gross details A-Rod’s reported affairs with hookers. A staffer at the building allegedly told Gross that A-Rod had a grand-slam sex drive.

Bill Kostroun

Torrie Wilson watching the New York Yankees and Los Angeles Angels play a baseball game in April 2012.

“One time he had two go up, they came down and left, and 10 minutes later, Cameron Diaz walks in. He doesn’t care. I hate the guy. He thought he was God,” Gross said a staffer told him.